Coupling-on or bridging implement



Dec. 27, 1938 R. BARANowsew ZQMLZS@ ,COULING-ON OR BRIDGING IMPLEMENTFiled m. 1, 193e Patented Dec. 27, 1938 UNITED STATES PATENT 'OFFICERaoul Baranowsky, Berlin-Treptow, Germany,

assignor to General Electric Company, a corporation of New YorkApplication February 1, 1936, Serial No.' 62,003 In Germany February 2,1935 7 Claims.

In high-frequency telephony across power lines it is frequentlynecessary to bridge disconnecting places present in said lines, forinstance oilor disconnecting switches, in a manner corresponding to thehigh frequency. For this purpose a coupling condenser is arranged inseries with each end of the line, and there is connected to saidcondenser a coil for compensating the high-frequency reactance of thesaid con-denser, the two coils serving simultaneously for coupling thetwo resonant circuits thus established.

That arrangement and combination of the parts stated suffers from thedrawback that a change of the wave necessitates a change in theinductance of the coils, and as, as a rule, stationary coils are usedfor the purpose in view, it is necessary to change the position of thecoils in order to change the tuning. Another drawback of saidarrangement is that the coupling factor of such inductively coupledcircuits is comparatively slight. Besides, every wave length requires apreceding computation of the coil inductance.

This invention presents a coupling or bridging implement which is freefrom the above-mentioned drawbacks, the gist of the same residingtherein that for the highest frequency to be transmitted two resonantcircuits coupled and connected in parallel by a capacity are provided,said lcircuits being tuned to said frequency and coupled with oneanother in such a manner that the coupling means transmits a band offrequencies extending from the above-mentioned highest frequency to thelowest frequency occurring in the respective case. The arrangementaccording to the invention has thus the character of a multipart filter.

The invention is illustrated diagrammatically and by way of example onthe accompanying drawing which shows a bridging arrangement for ahigh-frequency communication transmitting apparatus across a power-linethat can be disconnected by an oil-switch.

In this example L denotes the power-line, O an oil-switch, S1 ahigh-frequence stopper arranged before said switch, S2 a stopperarranged behind the said switch, R1 denotes the high frequencyresistance of the line L on the portion up to the oil-switch, saidresistance being assumed to be concentrated, and R2 denotes theresistance behind the said switch. S denotes the high-frequencygenerator, and E is the high-frequency receiver, both (S and E) beingadapted either for sound-transmission or for current-mark transmissionor for both. C1 is the coupling-condenser, on which the high-frequencyenergy is drawn from the line L before the stopper S1. C2 is thecoupling condenser, on which the high-frequency energy is re-conductedto the line L behind the stopper S2. Li is a coil for the compensationof the capacitive reactance ofthe coupling-condenser C1. L2 is just sucha coil for the coupling-condenser C2, and K denotes an adjustablecondenser.

The high-frequency produced by the generator Srpasses across thecoupling condenser C1, the coils L1 and Lzcr the tunable condenser Krespectively, and the coupling condenser C2 to the receiver E.

It appears from the drawing that the entire arrangement and combinationof the parts, across which the high-frequency passes, can becomprehended as a system of two oscillatory circuits connected up inparallel and coupled with one another across the condenser K, thecapacity of which can be adjusted. The one of said circuits comprisesthe generator S, the resistance R1, the coupling condenser C1 and theinductance L1 in combination with the wire connecting said members withone another, and the earth forming the return path. The otheroscillatory circuit comprises the high-frequency receiver E, the waveresistance R2, the coupling condenser C2 and the inductanc L2 incombination with the wire connecting these members with one another, andthe earth constituting the return path.

Supposing that the two oscillatory circuits are tuned to the highestfrequency tobe transmitted, then by appropriate adjustment of thetunable condenser K the coupling means in accordance with the presentinvention transmits the band of frequencies extending from theaforementioned highest frequency to the lowest frequency to betransmitted. 'Ihat adjustment can obviously be carried out in thesimplest way and presents the advantage that it can be effected at anytime and especially also at an open line without an eX- change of anyparts and without any change of the coil adjustment. Therefore theentire highfrequency system receives by thev coupling as described aband-characteristic, the breadth of which can be varied in a simplemanner.

I claim:

1. The combination, in a system for coupling two power lines togetherfor carrier currents having frequencies spaced apart by a desired rangeof frequencies, of a pair of oscillatory circuits tuned to one of saidfrequencies, one of said oscillatory circuits comprising the impedanceof one of said power lines and the other oscillatory circuit comprisingthe impedance of the other of said power lines, and a reactance elementto couple said oscillatory circuits and to resonate with the reactanceof said oscillatory circuits at a frequency spaced from said onefrequency by said desired range.

2. The combination, in a system for coupling two power lines togetherfor carrier currents having frequencies spaced apart by a desired rangeof frequencies, of a pair of oscillatory circuits tuned to one of saidfrequencies, one of said oscillatory circuits comprising the impedanceof one of said power lines and a branch across said line and the otherof said oscillatory circuits comprising the impedance of the other ofsaid lines and a branch across said other line, and a reactance elementconnected between said branches to couple said oscillatory circuits andto resonate with the reactance of said oscillatory circuits at afrequency spaced from said one frequency by said desired range.

3. The combination, in a system for coupling two power lines togetherfor carrier currents having frequencies spaced apart by a desired range,of a band-pass network comprising two oscillatory circuits tuned to thesame frequency, each of said oscillatory circuits including a respectiveone of said power lines, and a reactance element to couple saidoscillatory circuits, and to resonate with said oscillatory circuits ata different frequency, said frequencies being spaced apart by saidrange.

4. In a system for coupling two power lines together for carriercurrents having frequencies spaced apart by a desired range, a band-passnetwork having low attenuation for all currents in said range comprisinga series connection across each line, each series connection comprisinginductance and a condenser, and a reactance connected between saidseries connections.

5. In a system for coupling two power lines together for carriercurrents having frequencies spacedapart by a desired range, a band-passnetwork for said carrier currents comprising three condensers connectedin series between said power lines, and a pair of inductances, eachinductance being connected between ground and a respective point onopposite sides of the intermediate of said condensers.

6. The combination, in a network for transmission of a band offrequencies from a current source to a load, of a pair of oscillatorycircuits, one of said circuits comprising an inductance and a condenserconnected in series across said source and proportioned to resonate withthe impedance of said source at a frequency at one extremity of thefrequency range to be transmitted, the other of said circuits comprisingan inductance and a condenser connected in series across Said load and`proportioned to resonate with the impedance of said load at saidfrequency, and a reactance to connect together said oscillatory circuitsand to resonate with the reactance of said circuits at a frequency atthe opposite extremity of said range whereby said network offers lowimpedance to currents supplied to said one of said oscillatory circuitshaving any frequency within said' range.

7. In a system for coupling a source of currents having frequenciesextending over a wide range to a load, the combination of a pair ofirnpedances, one of said impedances comprising an inductance andacondenser connected in series across said source and proportioned toresonate

